Taxi lane debate
Take a look on google maps and have a look at the geography of the airport. An extended taxi way is not as simple as laying down an extra 900m of asphalt. You would need to move the existing fuel farm for starters to get an extension to the North. This would involve moving pipes and tanks and all sorts of other infrastructure. You would also need to move the existing ILS equipment to the opposite side of the runway. Whilst all of this is happening you would need to provide contingency for loss of these services again costing money. All of a sudden a few million turns into tens of millions. Who would pay for that? Pax certainly won't due to the government already piling on good ol APD and all the other taxes.
The alternative is to build an extended taxiway on the other side... You then introduce a risk of an extra runway crossing which means more risk of runway incursions with more risk of accidents...
Cambridge and London CIty require a backtrack along with a few other airports in this country.
Ideas of new terminals and extended runways etc are great ideas but you need high pax numbers to justify the massive cost involved. BAA is a large company and profitable but everyone seems to forget that the investment money ultimately comes from the customer... If pax numbers are low you either make the best of what you have or you raise the cost to the consumer and face losing them... Regardless of whether or not BAA have sold Edinburgh and about to inherit millions from its sale, each airport is in control of its own budget and raising its own profits so it's not as simple as sharing the sale money.